Characters in Noon Wine are drawn from those visual memories Porter examines in her essay about the story. Helton is drawn from the lonely figure of a man playing a harmonica on a cabin porch. The farmer and wife visiting her grandmother provided the outlines for the Thompsons, but Porter's artistry fleshes them out and balances this small cast of characters in elegant simplicity.

The opening characterization of Thompson as outwardly guffawing while inwardly scheming when he meets Helton is artfully reprised in the characterization of Hatch. The dislike Thompson immediately feels toward Hatch is founded in fact upon qualities they share, prefiguring the downward spiral of Thompson's idea of himself.

The weak and socially superior Mrs. Thompson provides the perfect reinforcement for Mr. Thompson's rise and fall. Her watery eyes are emblematic of the difficulty of seeing the truth in her husband's action.

Helton remains a distant, lonely figure whose human longings are expressed only in his harmonica playing. Quite appropriately, he never is allowed to speak directly to the Thompsons or to the reader about his own guilt in killing his brother. His nine years of labor in isolation are summed up in the money he sends his mother. Helton has also felt the insufferable weight of guilt.